:root {
  color-scheme: light dark;
  --bg: #f7f7f8;
  --card: #ffffff;
  --text: #18181b;
  --muted: #71717a;
  --border: #e4e4e7;
  --primary: #2563eb;
  --primary-text: #ffffff;
  --danger: #dc2626;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0a0a0b;
    --card: #18181b;
    --text: #fafafa;
    --muted: #a1a1aa;
    --border: #27272a;
    --primary: #3b82f6;
    --danger: #f87171;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 16px;
  background: var(--bg);
  color: var(--text);
  font: 15px/1.5 system-ui, -apple-system, "Segoe UI", sans-serif;
}
main {
  width: 100%;
  max-width: 380px;
  padding: 28px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
}
.brand { margin: 0 0 20px; font-weight: 600; letter-spacing: -0.01em; }
h1 { margin: 0 0 8px; font-size: 20px; }
p { margin: 0 0 12px; color: var(--muted); }
label { display: block; margin: 12px 0 4px; font-size: 13px; font-weight: 500; }
input {
  width: 100%;
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: transparent;
  color: inherit;
  font: inherit;
}
button {
  width: 100%;
  margin-top: 16px;
  padding: 9px 12px;
  border: 0;
  border-radius: 8px;
  background: var(--primary);
  color: var(--primary-text);
  font: inherit;
  font-weight: 500;
  cursor: pointer;
}
button:disabled { opacity: 0.6; cursor: default; }
.error { color: var(--danger); }
[hidden] { display: none !important; }